The document describes the preparation and standardization of various molar and normal solutions of oxalic acid and sodium hydroxide. It involves preparing solutions of known concentrations and titrating them against each other using phenolphthalein as an indicator to determine their exact concentrations. The concentrations prepared and standardized include 1M, 0.1M, 1N and 0.1N of oxalic acid and sodium hydroxide.

1. Pharmaceutical Analysis- I
Unit I
Preparation and Standardization of Various Molar and
Normal Solutions
Presented By:
Richa Shakya
Associate Professor
Faculty of Pharmaceutical Sciences
Rama University, Kanpur

2. Preparation and Standardization of 1M Oxalic Acid
Oxalic Acid - M.Wt - 126.07
Preparation of 1M Oxalic Acid Solution : Dissolve an accurately weighed amount of 126.07 gm of Oxalic acid in
sufficient amount of water to give or to produce 1000 ml.
Principle : It is an example of alkalimetry. When a strong base is titrated with a weak acid, the salt produced in the reaction
is not completely hydrolysed and the pH of the resultant solution at the end-point is exactly 7.0 . Oxalic Acid, a weak acid, is
standardised by titration with a strong base, NaOH.
The following reaction takes place when NaOH is titrated with Oxalic Acid.
2 (COOH) + 2 NaO H 2(COONa) + 2 H2O
In this titration, for detecting the end-point Phenolphthalein solution is used as indicator.

3. Preparation and Standardization of 1M Oxalic Acid
Procedure :
Preparation of 1M NaOH Solution : Dissolve an accurately weighed amount of 40 gm of NaOH in sufficient
amount of water to give or to produce 1000 ml.
Procedure for Standardisation of 1M Oxalic Acid : Take 10 ml of 1M NaOH solution into a conical flask and add
2 or 3 drops of phenolphthalein indicator. Titrate the contents of the flask against Oxalic acid solution until the pink
colour disappears. Repeat the titration to get concordant values. Note the result.

4. Formula
The Molarity of Oxalic Acid is calculated using the formula :
M1V1 = M2V2
where , V1 = Volume of 1M NaOH solution = 10 ml
M1 = Molarity of NaOH solution = 1M
V2 = Volume of Oxalic acid solution rundown (Average Burette Reading)
M2 = Molarity of Oxalic acid =?

5. Preparation and Standardization of 0.1M Oxalic Acid
Oxalic Acid - M.Wt - 126.07
Preparation of 0.1M Oxalic Acid Solution : Dissolve an accurately weighed amount of 12.607 gm of Oxalic acid in
sufficient amount of water to give or to produce 1000 ml.
Principle : It is an example of alkalimetry. When a strong base is titrated with a weak acid, the salt produced in the
reaction is not completely hydrolysed and the pH of the resultant solution at the end-point is exactly 7.0 . Oxalic Acid, a
weak acid, is standardized by titration with a strong base, NaOH.
The following reaction takes place when NaOH is titrated with Oxalic Acid.
2(COOH) + 2NaOH 2(COONa) + 2 H2O
In this titration, for detecting the end-point Phenolphthalein solution is used as indicator.

6. Preparation and Standardization of 0.1M Oxalic Acid
Procedure :
Preparation of 0.1M NaOH Solution : Dissolve an accurately weighed amount of 4 gm of NaOH in sufficient amount of water to
give or to produce 1000 ml .
Procedure for Standardisation of 0.1M Oxalic Acid : Take 10 ml of 0.1M NaOH solution into a conical flask and add 2 or 3
drops of phenolphthalein indicator. Titrate the contents of the flask against Oxalic acid solution until the pink colour disappears. Repeat
the titration to get concordant values. Enter the values in a tabular form

7. Preparation and Standardization of 0.1M Oxalic Acid
The Molarity of Oxalic Acid is calculated using the formula :
M1V1=M2V2
where ,
V1 = Volume of 0.1M NaOH solution = 10 ml
M1 = Molarity of NaOH solution = 0.1M
V2 = Volume of Oxalic acid solution rundown (Average Burette Reading)
M2 = Molarity of Oxalic acid =?

8. Preparation and Standardization of 1N Oxalic Acid
Oxalic Acid - M.Wt - 126.07
Preparation of 1N Oxalic Acid Solution : Dissolve an accurately weighed amount of 63.035 gm of Oxalic acid in sufficient
amount of water to give or to produce 1000 ml.
Principle : It is an example of alkalimetry. When a strong base is titrated with a weak acid, the salt produced in the reaction
is not completely hydrolysed and the pH of the resultant solution at the end-point is exactly 7.0 . Oxalic Acid, a weak acid, is
standardised by titration with a strong base, NaOH.
The following reaction takes place when NaOH is titrated with Oxalic Acid.
2 (COOH) + 2NaOH 2(COONa) + 2 H2O
In this titration, for detecting the end-point Phenolphthalein solution is used as indicator.

9. Preparation and Standardization of 1N Oxalic Acid
Procedure :
Preparation of 1N NaOH Solution : Dissolve an accurately weighed amount of 40 gm of NaOH in sufficient amount of
water to give or to produce 1000 ml .
Procedure for Standardization of 1N Oxalic Acid : Take 10 ml of 1N NaOH solution into a conical flask and add 2 or 3
drops of phenolphthalein indicator. Titrate the contents of the flask against Oxalic acid solution until the pink colour
disappears. Repeat the titration to get concordant values. Note the result.

10. Formula
The Normality of Oxalic Acid is calculated using the formula :
N1V1=N2V2
where ,
V1 = Volume of 1N NaOH solution = 10 ml
N1 = Normality of NaOH solution = 1N
V2 = Volume of Oxalic acid solution rundown (Average Burette Reading)
N2 = Normality of Oxalic acid =?

11. Preparation and Standardization of 0.1N Oxalic Acid
Oxalic Acid - M.Wt - 126.07
Preparation of 0.1N Oxalic Acid Solution : Dissolve an accurately weighed amount of 6.3 gm of Oxalic acid in
sufficient amount of water to give or to produce 1000 ml.
Principle : It is an example of alkalimetry. When a strong base is titrated with a weak acid, the salt produced in the
reaction is not completely hydrolyzed and the pH of the resultant solution at the end-point is exactly 7.0 . Oxalic Acid, a
weak acid, is standardized by titration with a strong base, NaOH. The following reaction takes place when NaOH is
titrated with Oxalic Acid.
2 (COOH ) + 2 NaOH 2(COONa) + 2 H2O
In this titration, for detecting the end-point Phenolphthalein solution is used as indicator.

12. Preparation and Standardization of 0.1N Oxalic Acid
Procedure :
Preparation of 0.1N NaOH Solution : Dissolve an accurately weighed amount of 4 gm of NaOH in sufficient
amount of water to give or to produce 1000 ml .
Procedure for Standardization of 0.1N Oxalic Acid : Take 10 ml of 0.1N NaOH solution into a conical flask
and add 2 or 3 drops of phenolphthalein indicator. Titrate the contents of the flask against Oxalic acid solution
until the pink colour disappears. Repeat the titration to get concordant values. Note the result.

13. Formula
The Normality of Oxalic Acid is calculated using the
formula :
N1V1=N2V2
where ,
V1 = Volume of 0.1N NaOH solution = 10 ml
N1 = Normality of NaOH solution = 0.1N
V2 = Volume of Oxalic acid solution rundown (Average Burette
Reading)
N2 = Normality of Oxalic acid =?

14. Preparation and Standardization of 1M Sodium Hydroxide
Sodium Hydroxide - M.Wt - 40
Preparation of 1M Sodium Hydroxide Solution : Dissolve an accurately weighed amount of 40 gm of Sodium
Hydroxide in sufficient amount of water to give or to produce 1000 ml.
Principle : It is an example of acidimetry. When a weak acid is titrated with a strong base, the salt produced in the
reaction is completely hydrolysed and the pH of the resultant solution at the endpoint is more than 7.0 (Alkaline).
Sodium hydroxide, a strong base, is standardized by titration with a weak acid, Oxalic acid. The following reaction
takes place when Oxalic Acid is titrated with NaOH.
2 (COOH ) + 2 NaOH 2(COONa) + 2 H2O
In this titration, for detecting the end-point Phenolphthalein solution is used as indicator.

15. Preparation and Standardization of 1M Sodium Hydroxide
Procedure :
Preparation of 1M Oxalic Acid Solution : Dissolve an accurately weighed amount of 126.07 gm of Oxalic Acid in
sufficient amount of water to give or to produce 1000 ml .
Procedure for Standardisation of 1M Sodium Hydroxide : Take 10 ml of 1M Oxalic Acid solution into a conical
flask and add 2 or 3 drops of phenolphthalein indicator. Titrate the contents of the flask against Sodium Hydroxide
solution until a permanent pink colour is obtained. Repeat the titration to get concordant values. Note the result.

16. Formula
The Molarity of NaOH is calculated using the formula :
M1V1=M2V2
where ,
V1 = Volume of 1M Oxalic Acid solution = 10 ml
M1 = Molarity of Oxalic Acid solution = 1M
V2 = Volume of NaOH solution rundown (Average Burette
Reading)
M2 = Molarity of NaOH =?

17. Preparation and Standardisation of 0.1M Sodium Hydroxide
Sodium Hydroxide - M.Wt - 40
Preparation of 0.1M Sodium Hydroxide Solution : Dissolve an accurately weighed amount of 4gm of Sodium
Hydroxide in sufficient amount of water to give or to produce 1000 ml.
Principle : It is an example of acidimetry. When a weak acid is titrated with a strong base, the salt produced in the
reaction is completely hydrolysed and the pH of the resultant solution at the endpoint is more than 7.0 (Alkaline).
Sodium hydroxide, a strong base, is standardised by titration with a weak acid, Oxalic acid. The following reaction
takes place when Oxalic Acid is titrated with NaOH.
2(COOH) + 2NaOH 2(COONa) + 2 H2O
In this titration, for detecting the end-point Phenolphthalein solution is used as indicator.

18. Formula
The Molarity of NaOH is calculated using the formula :
M1V1=M2V2
where ,
V1 = Volume of 0.1M Oxalic Acid solution = 10 ml
M1 = Molarity of Oxalic Acid solution = 0.1M
V2 = Volume of NaOH solution rundown (Average Burette
Reading)
M2 = Molarity of NaOH =?

19. Preparation and Standardization of 1N Sodium Hydroxide
Sodium Hydroxide - M.Wt - 40
Preparation of 1N Sodium Hydroxide Solution : Dissolve an accurately weighed amount of 40gm of Sodium
Hydroxide in sufficient amount of water to give or to produce 1000 ml.
Principle : It is an example of acidimetry. When a weak acid is titrated with a strong base, the salt produced in
the reaction is completely hydrolysed and the pH of the resultant solution at the endpoint is more than 7.0
(Alkaline). Sodium hydroxide, a strong base, is standardised by titration with a weak acid, Oxalic acid. The
following reaction takes place when Oxalic Acid is titrated with NaOH.
2(COOH) + 2NaOH 2(COONa) + 2 H2O
In this titration, for detecting the end-point Phenolphthalein solution is used as indicator.

20. Preparation and Standardization of 1N Sodium Hydroxide
Procedure :
Preparation of 1N Oxalic Acid Solution : Dissolve an accurately weighed amount of 63.035 gm of Oxalic Acid in
sufficient amount of water to give or to produce 1000 ml .
Procedure for Standardisation of 1N Sodium Hydroxide : Take 10 ml of 1N Oxalic Acid solution into a conical
flask and add 2 or 3 drops of phenolphthalein indicator. Titrate the contents of the flask against Sodium Hydroxide
solution until a permanent pink colour is obtained. Repeat the titration to get concordant values. Note the readings.

21. Formula
The Normality of NaOH is calculated using the
formula :
N1V1=N2V2
where ,
V1 = Volume of 1N Oxalic Acid solution = 10 ml
N1 = Normality of Oxalic Acid solution = 1N
V2 = Volume of NaOH solution rundown (Average Burette
Reading)
N2 = Normality of NaOH =?

22. Preparation and Standardization of 0.1N Sodium
Hydroxide
Sodium Hydroxide - M.Wt - 40
Preparation of 0.1N Sodium Hydroxide Solution : Dissolve an accurately weighed amount of 4gm of Sodium Hydroxide i
sufficient amount of water to give or to produce 1000 ml.
Principle : It is an example of acidimetry. When a weak acid is titrated with a strong base, the salt produced in the reaction i
completely hydrolysed and the pH of the resultant solution at the endpoint is more than 7.0 (Alkaline). Sodium hydroxide,
strong base, is standardised by titration with a weak acid, Oxalic acid. The following reaction takes place when Oxalic Acid i
titrated with NaOH.
2(COOH) + 2NaOH 2(COONa) + 2 H2O
In this titration, for detecting the end-point Phenolphthalein solution is used as indicator.

23. Preparation and Standardization of 0.1N Sodium
Hydroxide
Preparation of 0.1N Oxalic Acid Solution : Dissolve an accurately weighed amount of 6.3 gm of Oxalic
Acid in sufficient amount of water to give or to produce 1000 ml .
Procedure for Standardization of 0.1N Sodium Hydroxide : Take 10 ml of 0.1N Oxalic Acid solution
into a conical flask and add 2 or 3 drops of phenolphthalein indicator. Titrate the contents of the flask
against Sodium Hydroxide solution until a permanent pink colour is obtained. Repeat the titration to get
concordant values. Note the readings.

24. Formula
The Normality of NaOH is calculated using the formula :
N1V1=N2V2
where ,
V1 = Volume of 0.1N Oxalic Acid solution = 10 ml
N1 = Normality of Oxalic Acid solution = 0.1N
V2 = Volume of NaOH solution rundown (Average Burette Reading)
N2 = Normality of NaOH =?